1. Appropriate use of vitamin k in patients on warfarin with
supratherapeutic international normalized ratio: Evaluation
of practice in a medical facility
Ihongbe, F., Pharm.D. Candidate;1 Petrov, K., PharmD, BCPS;1 Chang, M., PharmD, BCPS2
1 Bernard J. Dunn School of Pharmacy, Shenandoah University, Ashburn, Virginia
2 INOVA Loudoun Hospital, Leesburg, Virginia
Introduction
Methods
Results
References
Background
o CHEST guidelines recommend no administration of vitamin K
for patients with an international normalized ratio (INR) less
than 10.1
o For patients with an INR greater than 10 without significant
bleeding, vitamin K 2.5-5 mg orally is recommended.1
o For patients with major bleeding, vitamin K 5-10 mg
intravenously is recommended.1
o Adherence to recommendation guidelines in this medical
facility is unknown.
Objective
o To evaluate in a medical facility, the appropriate use of
vitamin K in comparison with CHEST guidelines in patients on
warfarin with supratherapeutic INR, patients scheduled for
surgery, and patients with bleeding events,
o This cross-sectional descriptive study was conducted at a
small community hospital in Virginia.
o Patient medical records were screened from May 2015 to
April 2016.
o Study population included patients (N=43) who were admitted
on warfarin.
o International normalized ratio values prior to administration of
vitamin K were recorded and divided into three categories:
<4.5, 4.5-10, and >10
o Study sample was divided into 3 groups based on vitamin K
use: patients scheduled for surgery, patients with bleeding
events, and patients with supratherapeutic INR from warfarin
therapy
o Analyses was conducted using Microsoft excel 2013
1. Wigle, P., Hein, B., Bloomfield, H. E., Tubb, M., & Doherty,
M. (2013). Updated guidelines on outpatient
anticoagulation. American family physician, 87(8).
Discussion
o Vitamin K utilization was consistent with guideline
recommendations for a total of 4 (9%) patients.
o A dose of 5 mg of vitamin K was the most frequently used
dosing strategy.
o Vitamin K utilization in patients with bleeding events had the
most consistency with guideline recommendations 3 (33%).
o This study shows that the use of vitamin K in this community
hospital was not consistent with recommendation guidelines.
o It also demonstrates that there is a difference between clinical
judgment and guideline adherence.
o Although, it may not be possible to achieve 100% congruence
with recommendation guidelines, adherence to
recommendation guidelines may decrease the amount of
inappropriate use of vitamin k.
o Education and judicious use of vitamin K will also help improve
patient outcome and reduce healthcare costs.
No relevant conflict of interest to disclose.
Conflict of Interest
Figure 1. Percent distribution of study sample by vitamin K use
46.5
20.9
32.6
0
5
10
15
20
25
30
35
40
45
50
Scheduled for surgery Bleeding event Supratherapeutic INR
Percent(%)
Patients scheduled for surgery (n=20)
INR prior to Vitamin K administration
<4.5 (n=18) 4.5-10 (n=1) >10 (n=1)
Route of administration
Oral IV Oral IV Oral IV
2.5mg (n=6)
5mg (n=4)
10mg (n=1)
2.5mg (n=1)
5mg (n=3)
10mg (n=3)
5mg (n=1) - - 5mg (n=1)
Patients with bleeding events (n=9)
INR prior to Vitamin K administration
<4.5 (n=4) 4.5-10 (n=5) >10 (n=0)
Route of administration
Oral IV Oral IV Oral IV
5mg (n=1) 2mg (n=1)
10mg (n=2)
2.5mg (n=3)
10mg (n=1)
5mg (n=1) - -
Patients with supratherapeutic INR (n=14)
INR prior to Vitamin K administration
<4.5 (n=0) 4.5-10 (n=13) >10 (n=1)
Route of administration
Oral IV Oral IV Oral IV
- - 2.5mg (n=4)
5mg (n=4)
2mg (n=1)
5mg (n=3)
10mg (n=1)
5mg (n=1) -
Table 1. Vitamin K use by INR, route of administration and dose